Pathogenic potential of environmental Klebsiella pneumoniae isolates
Carsten Struve1, Karen Angeliki Krogfelt
1Department of Gastrointestinal and Parasitic Infections, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark.
Abstract:
Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. K. pneumoniae infections can occur at nearly any body site; however, urinary tract infections and infections of the respiratory tract predominate. Infections are frequently preceded by gastrointestinal colonization, and the gastrointestinal tract is believed to be the most important reservoir for transmission of the bacteria. In contrast to many other bacterial pathogens, K. pneumoniae is ubiquitous in nature. Several studies have described Klebsiella isolates of environmental origin to be nearly identical to clinical isolates with respect to several phenotypic properties. However, the pathogenic potential of environmental K. pneumoniae isolates is essentially unknown. We have evaluated the virulence of K. pneumoniae strains of environmental and clinical origin directly in animal models, i.e. in urinary tract infection and intestinal colonization models. Furthermore, the ability to adhere to and invade human epithelial cell lines was examined. Although strain-to-strain differences were observed in the individual infection models, overall, strains of environmental origin were found to be as virulent as strains of clinical origin. The ubiquity of K. pneumoniae in nature and the general ability of K. pneumoniae strains to infect susceptible hosts might explain the high frequency of opportunistic infections caused by this species.
Insights
Environmental Klebsiella pneumoniae strains are as virulent as clinical ones, suggesting nature is a significant reservoir for this opportunistic pathogen. This finding helps explain frequent nosocomial infections.
Area of Science:
- Microbiology
- Infectious Diseases
- Pathogen Research
Background:
- Klebsiella pneumoniae is a major cause of hospital-acquired infections, particularly urinary tract and respiratory infections.
- Gastrointestinal colonization is a key reservoir for K. pneumoniae transmission.
- While ubiquitous in nature, the pathogenic potential of environmental K. pneumoniae is largely unknown.
Purpose of the Study:
- To evaluate and compare the virulence of environmental and clinical Klebsiella pneumoniae strains.
- To assess the pathogenic potential of environmental K. pneumoniae in relevant infection models.
- To examine the adherence and invasion capabilities of environmental strains in human epithelial cells.
Main Methods:
- Virulence assessment in animal models for urinary tract infections and intestinal colonization.
- In vitro assays evaluating adherence to and invasion of human epithelial cell lines.
- Comparative analysis of environmental and clinical K. pneumoniae isolates.
Main Results:
- Environmental K. pneumoniae strains demonstrated comparable virulence to clinical strains in animal models.
- Strain-specific variations in virulence were observed across different infection models.
- Environmental isolates exhibited similar abilities to adhere to and invade human epithelial cells as clinical isolates.
Conclusions:
- Environmental strains of Klebsiella pneumoniae possess pathogenic potential similar to clinical strains.
- The ubiquitous presence of virulent environmental K. pneumoniae contributes to opportunistic infections.
- Understanding environmental reservoirs is crucial for controlling K. pneumoniae infections.
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